of newaek



(No Model.)

B. WESTON.

PROCESS OF MAKING INGANDESCENTS.

No. 340,402. Patented Apr. 20, 1886.

$966685 frwenzor N. puns, Pholo-Lilhognphor, Wuhinglnn. v.1;

Urrrrn STATES EDWARD VESTON, OF NElVARK, NE\V JERSEY, ASSIGNOR TO THEUNITED STATES ELECTRIC LIGHTING COMPANY, OF NEl/V YORK, N. Y.

PROCESS OF MAKING INCANDESCENTS.

SPECIFICATION forming part of Letters Patent No, 340,402, dated April20. 1886.

Application filed January 4, 1886. Serial X0. H1611. (No model.)

To all whom, it may concern.-

Be it known that I, EDWARD WESTON, a subject of the Queen of GreatBritain, and a resident of Newark, in the county of Essex and State ofNew Jersey, have invented certain new and useful Improvements inProcesses of Manufacturing Carbon Conductors for Incandescent Lamps, ofwhich the following is a specification, reference being had to [O thedrawing accompanying and forming a part of the same.

My improvements relate to the production of the carbonized'conductingstrips or filaments for incandescent electric lamps, the ob- [5 jeot ofthe same being to produce more dense and perfect carbons free from thepresence of so-called occluded gases.

The treatment which my present invention involves is applied during thatportion or stage of the process of making carbons which consists inheating the blanks to a very high temperature in a closed muffleorretort for carbonizing them; and it consists in placing the said blanks,before they have become cool,

but after their carbouization has been effected as completely aspracticable, in a close vessel or chamber and withdrawing therefrom the1 heat, it remains at a temperature sufficiently air and gases by apump, or by any other means of producing a partial vacuum.

The complete process in detail is as follows: A large number of stripsor blanks are out, punched, or otherwise formed from a proper material.These are packed in an iron or plumbago box or muffle between sheets of5 carbon or in a carbon powder, the box closed and placed in a furnace.It is here subjected to a very intense heat until the carbonization ofthe strips has been effected to as perfect a degree as is practicable.The box or muffle is o'then taken out, and while at a white heat isplaced in a vessel or chamber which is so constructed that it may beclosed air-tight. With this an air-pump or vacuum apparatus is connectedand kept in operation until the muffle and its contents have nearly orentirely cooled ofl. By thus subjecting the carbons to the action of avacuum while cooling, the gases which they would otherwise retain arewithdrawn, and a carbon much more perfect in quality is produced at agreatly-reduced cost.

This process, to be practically and economically carried out, requiresthe use of certain devices, which the accompanying drawing illustrates.

A is a stout box, of iron or other refractory material, with acover, B,that may be applied to close the box air-tight. From this box leads atube or pipe, C, to an air-exhaust apparatus, D. The latter is hereshown as an ordinary mechanical exhaust-pump; but any other means ofproducing a vacuum may be employed. The pipe C at some intermediatepoint is formed in acoil, E, which is contained in a water-jacket, F, inwhich a How of cold water may be maintained to cool the air or 6 gas inthe pipe and prevent injury to the vacuum apparatus. The box A is alsoprovided with an air-inlet, G, and both the pipes C and G are providedwith suitable valves or cocks, f f.

H represents the muffle containing the carbons. It is desirable that itshould retain its heat as long as possible, and therefore it issurrounded, when placed in box A, bya packing of asbestos, (representedby the mats or pads K K.) Under these conditions, when a muffle is takenfrom the furnace at a white high to cause the evolution of gas from thecarbons for a considerable length .of time. So When the carbons havecooled so that there is no further evolution ofgas, the exhausting isstopped and air admitted through the pipe G. The muffle is then removedand the carbons treated and used in any of the usual ways.

The method heretofore employed in expelling the gases retained by theconductors of incandescent lamps has been to raise the conductors to ahigh degree of incandescence by an electric current after being mountedin the lamps, but before the latter are sealed off from the pumps. Thelabor and time required in doing this I have found to be very materiallyreduced by treating the carbons in the 5 manner which I have hereindescribed.

What I claim is- 1. The improvement in the process of making or treatingcarbon conductors, which consists in placing the carbons, after removalfrom it the carbonizing-furnace and while cooling, in a close vessel orchamber and exhausting the air and gas from the same. 2. Theimprovementin the process of treat- 5 mg carbon conductors, whichconsists in placing the 1n uflie, with the carbons contained therein,after removal from the carbonizingfurnace and while cooling, in a closevessel or chamber and exhausting the air and gas from 10 the same.

3. The method 'of treating carbons herein described, which consists intransferring the mufile, filled with carbons, from thecarbonizing-furnace to a close vessel orchamber, packing the muffle withasbestus to retard cooling, I5 and exhausting the air and gas from thevessel.

EDWARD WESTON.

\Vitnesses:

HENRY A. BECKMEYER, RICHARD WM. BLOEMEKE.

